Heater adapted to burn volatile fuels



March 29, 1966 M. c. L. SCHMITT 3,242,957

HEATER ADAPTED TO BURN VQLATILE FUELS Filed Jan. 21, 1965 2 Sheets-Sheet 1 Fig.1

INVEIVTUR B ylmwmww ATTORNEYS March 29, 1966 M. c. L. SCHMITT HEATER ADAPTED TO BURN VOLATILE FUELS 2. Sheets-Sheet 2 Filed Jan. 21, 1965 IMENTOR Mamre a CL. 545-1775? ATTORNEYS United States Patent HEATER ADAPTED T0 BURN VOLATILE FUEIS Manfred Carlhorst Linus Schmitt, Kelheim (Danube), Germany, assignor to Alrtiebolaget Eahco, Stockholm,

Sweden, a corporation of Sweden Filed Jan. 21, 1965, Ser. No. 426,901 Claims priority, application Sweden, Jan. 23, 1964, 341/ 64 3 Claims. (Cl. 158--28) The present invention relates to a heater adapted to burn volatile fuels and provided with a volatilization chamber for the fuel and especially intended for motor vehicles, said heater being provided with a substantially horizontal combustion chamber directly adjacent to which the volatilation chamber is situated, a fuel nozzle projecting into the volatilization chamber from above and a heating wire exactly below the fuel nozzle.

Examples of such heaters are shown in the Swedish Patents 176,718 and 176,719. A heater of that type is started in such a way that the heating wire (and a fan for the air supply) is connected to the electric source. When the heating wire has reached the desired temperature the fuel valve is opened and fuel drips down onto the heating wire and is vaporized to be ignited when the air is supplied. When a steady state temperature has been reached in the volatilization chamber the heating wire is disconnected from the electric source. In heaters of this kind a problem has arisen in connection with the fact that the voltage for the electrical system of the vehicles has a tendency to change from 6 volts to a higher voltage of 12 or 24 volts. In this connection it has been found necessary to wind the heating wire around a ceramic core. This means that a portion of the fuel which comes into contact with the colder core does not vaporize but drips down onto the bottom of the volatilization chamber. This is especially the case when using less volatile fuels, e.g. diesel oils.

This problem is according to the present invention solved in that a drop catcher in the shape of a plate is provided below the heating wire which plate is arranged with such an inclination that the edge of the plate lying nearest the combustion chamber is situated in a plane above the opposite edge of the plate. The fuel drops are caught by the plate and get opportunity to vaporize during the time they remain in the vicinity of the heating wire.

The invention will be further described in connection to the embodiment shown on the attached drawing, in which FIG. 1 is an axial longitudinal section through the central portions of a heater with a device according to the invention.

FIG. 2 shows in a perspective side view a detail of the heater according to FIG. 1.

FIG. 3 is a horizontal section through the detail according to FIG. 2.

In the drawing 1 designates a substantially cylindrical,

horizontally arranged combustion chamber the front por- "ice tion of which consists of the annular plates 2 and 3. A volatilization chamber lying in front of the combustion chamber, as seen in the direction of flow, is formed by the plate 4. Into this volatilization chamber there project a fuel nozzle 5 and a heating wire '6. Below said wire is provided a plate 7 the function of which will be further described in the following.

The fan 8 supplies combustion air through the annular passage 9 and air to be heated through the annular channel 1d. The combustion air is supplied to the combustion chamber as primary air through the opening 13 via the openings 11 and the annular channel 12 and as secondary air through the openings 15 from the channel 12 and through the clearance 16. The fitting 14 (FIGS. 2 and 3) is provided for the attachment of a thermostat which responds to the temperature of the volatilization chamber.

The heating wire is wound onto a ceramic core 17. The plate 7 is provided directly below the heating wire and at an angle against the horizontal plane so that that edge of the plate lying nearest to the combustion chamber is situated in a plane above the opposite edge. In this way it is prevented that fuel drips from the ceramic core down onto the bottom of the volatiliz-ation chamber and therefrom further down into the channel 12. The plate catches the drops and holds them on its surface while they flow toward the wall 4 of the volatilization chamber during which time volatilization takes place. If the plate was not inclined the fuel drops would not spread so easily over the surface. The most suitable inclination of the plate has been found to be that at which the angle lies between 10 and 25 and especially if the angle is 15.

I claim:

1. Heater adapted to burn volatile fuels and provided with a volatilization chamber for the fuel and especially intended for motor vehicles, said heater comprising a substantially horizontal combustion chamber, a volatilization chamber contiguous to and communicating with said combustion chamber, a fuel nozzle projecting into the volatilization chamber from above and a heating wire vertically below the fuel nozzle, a drop-catcher plate connected to said volatilization chamber and positioned directly below the heating wire, said plate being inclined relative to the horizontal such that the edge of the plate lying nearest the combustion chamber is above the opposite edge of the plate.

2. Heater according to claim 1, wherein the plate taken with the horizontal forms an angle between 10 and 25.

3. Heater according to claim 1, wherein the plate taken with the horizontal forms an angle of 15.

References Cited by the Examiner UNITED STATES PATENTS 2,489,716 11/1949 McCollum 15828 2,712,352 7/1955 Meanor et al. 158-280 JAMES W. WESTHAVER, Primary Examiner. 

1. HEATER ADAPTED TO BURN VOLATILE FUELS AND PROVIDED WITH A VOLATILIZATION CHAMBER FOR THE FUEL AND ESPECIALLY INTENDED FOR MOTOR VEHICLES, SAID HEATER COMPRISING A SUBSTANTIALLY HORIZONTAL COMBUSTION CHAMBER, A VOLATILIZATION CHAMBER CONTIGUOUS TO AND COMMUNICATING WITH SAID COMBUSTION CHAMBER, A FUEL NOZZLE PROJECTING INTO THE VOLATILIZATION CHAMBER FROM ABOVE AND A HEATING WIRE VERTICALLY BELOW THE FUEL NOZZLE, A DROP-CATCHER PLATE CONNECTED TO SAID VOLATILIZATION CHAMBER AND POSITIONED DIRECTLY BELOW THE HEATING WIRE, SAID PLATE BEING INCLINED RELATIVE TO THE HORIZONTAL SUCH THAT THE EDGE OF THE PLATE LYING NEAREST THE COMBUSTION CHAMBER IS ABOVE THE OPPOSITE EDGE OF THE PLATE. 